I have a new 4TB G-Drive and I'm having a problem when I switch between firewire and USB 3.0 interfaces. I set the drive using firewire 800. When I then moved the drive to use with USB 3.0, I get an error that the drive is not readable. However, if I switch the connection back to firewire 800, the drive is recognized and I can see the content as expected. Please note that I already installed the USB 3.0 Firmware Update that is on the G-Tech website and I keep geting the same error. My system is running Maveriks.

Thanks for posting. The issue you are having we do have a firmware fix for however the firmware listed on the website is for a later issue and is not cumulative. I can email you the firmware update for correcting this issue. Be advised the firmware update for this issue will format the drive and needs to be performed over usb. So please backup any data on the drive before performing the firmware update if it is not backed up already.

snowboardingbum wrote:Hi. I am having the exact same issue. Used the firmware on the site and didn't fix it. Did SMC and PRAM reset... nothing.

Is there a different firmware? Can I get that emailed to me?

Thanks.... driving me crazy on my new 4TB drive.

I'm also having a similar problem with my 2-TB 5th generation (FW800 and USB3) G-Drive. This drive has worked perfectly using FW800 for about 8 months, but as soon as I switch to USB - via a USB2 port on my iMac - I have had exactly the same problem.

Whilst using Carbon Copy Cloner to take a disk copy to the G-Drive, the iMac loses connection with the drive after a variable time of an hour or so, and all disk volumes on the G-Drive are no longer mounted. I can only get them mounted by restarting the iMac, but then I get the "not unmounted cleanly messages" and on trying to Repair the volume, the Repair fails and the only way out is to reformat (re-partition) the drive. I have repeated this cycle several times, but in each case, the result is an unrepairable volume.

Switching back to Firewire (FW800), once the drive has been repartitioned, everything works as before, and there has been no problem for several days now. So this would seem to be a problem affecting the USB interface.

I have not applied the available Firewire firmware update (if my drive were to need it) as this doen't appear to be relevant to this problem, but there would appear to be a firmware update for this USB problem that is not available from the download site.

Thanks for posting. The alternate connection issue between the firewire and usb was only on some early 4TB models. If you started on one connection and moved to the other it would say disk could not be read but if you move it back the first connection it would work fine. If you are getting corruption when moving between connections especially on a 2TB unit I would suggest replacing the drive under warranty. You can file a RMA here. http://prod.g-technology.com/support/warranty_rma.cfm

Dustin F wrote:Hi JP-Cheshire,Thanks for posting. The alternate connection issue between the firewire and usb was only on some early 4TB models. If you started on one connection and moved to the other it would say disk could not be read but if you move it back the first connection it would work fine. If you are getting corruption when moving between connections especially on a 2TB unit I would suggest replacing the drive under warranty. You can file a RMA here. http://prod.g-technology.com/support/warranty_rma.cfm

Dustin, Thanks for the prompt response. Since my append, I discovered that the latest firmware update referred to a USB3 problem, so I decided to apply this. Once I'd reformatted the drive (re-partitioned), I had more success but eventually I had the same problem - all volumes were no longer mounted, with the failure happening whilst data was being written to the disk.

At this stage I recalled one of your FAQ items about USB cables and USB cable lengths. So, instead of using the 3 metre / 10 feet cable that I wished to use - to hide the drive away and reduce the apparent noise it makes - I switched back to the cable supplied with the drive. This is about 0.75 metres / 2.5 feet long. Since then, everything has been fine.

So, my problem would seem to stem from using a long, supposedly USB3 capable cable, even though I am driving it via USB2. (And there is no evidence that there is actually anything wrong with the drive.)

That leaves one question. Is there a way of connecting the drive via USB where the drive is about 3 metres away? (It works fine on FW800 with a 4-5 metre cable.) Could one attach it via a powered hub, such that the hub "re-drives" the signals? I'm clutching at straws here but would like to move the drive away from my desktop if at all possible whilst still using USB. I would appreciate any suggestions.

Usually about 10ft is the limit that it communicates stably but it seems you are having some attenuation. Hubs usually add extra juice for bus powered drives for the drive to spin, not necessarily the data signal. Perhpas a slightly shorter cable would work for you.